<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>相对定位</title>
    <style>
        .top,.down{
            width: 200px;
            height: 200px;
        }
        .top{
            background-color: red;
            position: relative;
            top: 100px;
            left: 100px;
        }
        .down{
            background-color: blue;
        }
    </style>
</head>
<body>
    <!-- 相对定位是基于原来位置进行定位，在移动后不会出现浮动脱标，原先位置不会被占有 -->
    <div class="top"></div>
    <div class="down"></div>
</body>
</html>